/* ==========================================================================
   大象网络 (Daxiang Network) - 纯原生极速 CSS 样式表 (浅色/亮色主题)
   无任何第三方依赖 | 100% 响应式 | 清洁高质感浅色视觉
   ========================================================================== */

/* 1. 变量定义与全局重置 */
:root {
  --bg-main: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-hover: #f1f5f9;
  --bg-nav: rgba(255, 255, 255, 0.9);
  
  --primary: #4f46e5;
  --primary-hover: #4338ca;
  --primary-gradient: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
  --secondary-gradient: linear-gradient(135deg, #2563eb 0%, #0d9488 100%);
  --accent-gold: linear-gradient(135deg, #d97706 0%, #b45309 100%);
  
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-dim: #64748b;
  
  --border-color: #e2e8f0;
  --border-highlight: rgba(79, 70, 229, 0.3);
  
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --shadow-glow: 0 10px 30px rgba(79, 70, 229, 0.15);
  --shadow-card: 0 4px 20px -2px rgba(15, 23, 42, 0.05), 0 2px 6px -2px rgba(15, 23, 42, 0.03);
  
  --font-stack: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --max-width: 1200px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-main);
  color: var(--text-main);
  font-family: var(--font-stack);
  -webkit-font-smoothing: antialiased;
}

body {
  line-height: 1.6;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

ul {
  list-style: none;
}

img {
  max-width: 100%;
  height: auto;
}

/* 2. 通用布局与组件 */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.text-gradient {
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section-title {
  text-align: center;
  margin-bottom: 3.5rem;
}

.section-title h2 {
  font-size: 2.25rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
  color: var(--text-main);
}

.section-title p {
  color: var(--text-muted);
  font-size: 1.125rem;
  max-width: 600px;
  margin: 0 auto;
}

/* 按钮样式规范 - 适配手指触控 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.85rem 1.75rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all 0.25s ease;
  cursor: pointer;
  border: none;
  min-height: 48px;
  white-space: nowrap;
}

.btn-primary {
  background: var(--primary-gradient);
  color: #ffffff;
  box-shadow: 0 4px 15px rgba(79, 70, 229, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(79, 70, 229, 0.45);
}

.btn-secondary {
  background: #ffffff;
  color: var(--text-main);
  border: 1px solid var(--border-color);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.04);
}

.btn-secondary:hover {
  background: #f1f5f9;
  border-color: #cbd5e1;
  transform: translateY(-2px);
}

.btn-lg {
  padding: 1rem 2.25rem;
  font-size: 1.125rem;
  border-radius: var(--radius-md);
}

.btn-block {
  width: 100%;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.35rem 0.85rem;
  font-size: 0.85rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  background: rgba(79, 70, 229, 0.08);
  color: var(--primary);
  border: 1px solid rgba(79, 70, 229, 0.2);
}

/* 3. 顶部导航栏 */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--bg-nav);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  height: 72px;
  display: flex;
  align-items: center;
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.01em;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: var(--primary-gradient);
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 900;
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.25);
}

.logo-img {
  width: 38px;
  height: 38px;
  border-radius: 10px;
  object-fit: cover;
  box-shadow: 0 4px 12px rgba(79, 70, 229, 0.25);
  display: block;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-links a {
  font-size: 0.95rem;
  color: var(--text-muted);
  font-weight: 500;
  transition: color 0.2s ease;
}

.nav-links a:hover {
  color: var(--primary);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* 4. 主视觉区 (Hero Section) */
.hero {
  padding: 10rem 0 5rem;
  text-align: center;
  position: relative;
  background: radial-gradient(circle at 50% 20%, rgba(79, 70, 229, 0.08) 0%, transparent 65%);
}

.hero-badge {
  margin-bottom: 1.5rem;
}

.hero h1 {
  font-size: 3.5rem;
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 1.5rem;
  color: var(--text-main);
}

.hero p {
  font-size: 1.25rem;
  color: var(--text-muted);
  max-width: 780px;
  margin: 0 auto 2.5rem;
  line-height: 1.7;
}

.hero-cta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.25rem;
  margin-bottom: 4rem;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  max-width: 900px;
  margin: 0 auto;
  padding: 1.75rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
}

.stat-item h4 {
  font-size: 1.85rem;
  font-weight: 800;
  color: var(--primary);
  margin-bottom: 0.25rem;
}

.stat-item p {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin: 0;
}

/* 5. 产品核心优势 Section */
.features {
  padding: 6rem 0;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.25rem;
  box-shadow: var(--shadow-card);
  transition: all 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-5px);
  border-color: rgba(79, 70, 229, 0.4);
  box-shadow: var(--shadow-glow);
}

.feature-icon {
  width: 52px;
  height: 52px;
  background: rgba(79, 70, 229, 0.08);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--primary);
  margin-bottom: 1.5rem;
}

.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--text-main);
}

.feature-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* 6. 流媒体与 AI 支持 Section */
.eco-support {
  padding: 6rem 0;
  background: #f1f5f9;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.eco-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}

.eco-box {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-card);
}

.eco-box h3 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.eco-box p {
  color: var(--text-muted);
  margin-bottom: 1.75rem;
  font-size: 0.95rem;
}

.tags-wrapper {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.tag-item {
  background: #f8fafc;
  border: 1px solid var(--border-color);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  color: #334155;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* 7. 套餐价格对比表 Section */
.pricing {
  padding: 6rem 0;
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem 2rem;
  display: flex;
  flex-direction: column;
  position: relative;
  box-shadow: var(--shadow-card);
  transition: all 0.3s ease;
}

.pricing-card.popular {
  border: 2px solid var(--primary);
  background: linear-gradient(180deg, #f5f3ff 0%, #ffffff 100%);
  box-shadow: var(--shadow-glow);
  transform: scale(1.03);
}

.pricing-badge {
  position: absolute;
  top: -14px;
  right: 2rem;
  background: var(--primary-gradient);
  color: #fff;
  font-size: 0.8rem;
  font-weight: 700;
  padding: 0.3rem 0.9rem;
  border-radius: var(--radius-full);
  letter-spacing: 0.05em;
  box-shadow: 0 4px 10px rgba(79, 70, 229, 0.3);
}

.pricing-card h3 {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--text-main);
}

.pricing-card .desc {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-bottom: 1.75rem;
}

.pricing-amount {
  font-size: 2.5rem;
  font-weight: 900;
  color: var(--text-main);
  margin-bottom: 1.5rem;
  display: flex;
  align-items: baseline;
  gap: 0.25rem;
}

.pricing-amount span {
  font-size: 1rem;
  font-weight: 400;
  color: var(--text-muted);
}

.pricing-features {
  margin-bottom: 2rem;
  flex-grow: 1;
}

.pricing-features li {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 0.85rem;
}

.pricing-features li svg {
  color: #059669;
  flex-shrink: 0;
}

/* 8. 用户评价 Section */
.testimonials {
  padding: 6rem 0;
  background: #f1f5f9;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.testimonial-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-card);
}

.stars {
  color: #d97706;
  margin-bottom: 1rem;
  display: flex;
  gap: 0.25rem;
}

.testimonial-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 1.5rem;
  font-style: italic;
}

.user-info {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.user-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  color: #fff;
  font-size: 1rem;
}

.user-details h5 {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-main);
}

.user-details span {
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* 9. FAQ 常见问题 Section */
.faq {
  padding: 6rem 0;
}

.faq-grid {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.75rem;
  box-shadow: var(--shadow-card);
}

.faq-item h4 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 0.65rem;
}

.faq-item p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* 10. 全局 Call To Action Banner */
.cta-banner {
  padding: 5rem 0;
  background: linear-gradient(135deg, rgba(79, 70, 229, 0.08) 0%, rgba(124, 58, 237, 0.08) 100%);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
  text-align: center;
}

.cta-banner h2 {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 1rem;
  color: var(--text-main);
}

.cta-banner p {
  color: var(--text-muted);
  font-size: 1.15rem;
  margin-bottom: 2rem;
}

/* 11. 页脚 (Footer) 规范 */
.footer {
  padding: 3.5rem 0 2.5rem;
  background: #ffffff;
  border-top: 1px solid var(--border-color);
  text-align: center;
}

.footer-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 3rem;
  margin-bottom: 2rem;
}

.footer-nav a {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-main);
  transition: color 0.2s ease;
  padding: 0.5rem;
}

.footer-nav a:hover {
  color: var(--primary);
}

.footer-copyright {
  color: var(--text-dim);
  font-size: 0.875rem;
}

/* 12. 独立子页面通用样式 */
.page-wrapper {
  padding: 8rem 0 5rem;
  min-height: 80vh;
}

.page-header {
  margin-bottom: 3rem;
  text-align: center;
}

.page-header h1 {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 1rem;
  color: var(--text-main);
}

.page-header p {
  color: var(--text-muted);
  font-size: 1.1rem;
}

.content-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 3rem;
  line-height: 1.8;
  color: var(--text-muted);
  box-shadow: var(--shadow-card);
}

.content-card h2 {
  color: var(--text-main);
  font-size: 1.5rem;
  margin: 2rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
}

.content-card h2:first-child {
  margin-top: 0;
}

.content-card p {
  margin-bottom: 1.25rem;
  font-size: 1rem;
}

.content-card ul {
  list-style: disc;
  padding-left: 1.5rem;
  margin-bottom: 1.5rem;
}

.content-card li {
  margin-bottom: 0.5rem;
}

/* 13. 极简移动端响应式 (@media) 适配 */
@media (max-width: 992px) {
  .hero h1 {
    font-size: 2.75rem;
  }
  
  .features-grid,
  .pricing-grid,
  .testimonials-grid,
  .articles-grid {
    grid-template-columns: repeat(2, 1fr) !important;
  }
  
  .pricing-card.popular {
    transform: none;
  }
  
  .eco-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .header {
    height: 64px;
  }
  
  .nav-links {
    display: none; /* 移动端精简顶部导航，聚焦 CTA 点击 */
  }
  
  .hero {
    padding: 7rem 0 3.5rem;
  }
  
  .hero h1 {
    font-size: 2rem;
  }
  
  .hero p {
    font-size: 1rem;
  }
  
  .hero-cta {
    flex-direction: column;
    width: 100%;
  }
  
  .hero-cta .btn {
    width: 100%;
  }
  
  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.25rem;
    padding: 1.25rem;
  }

  .features-grid,
  .pricing-grid,
  .testimonials-grid,
  .articles-grid {
    grid-template-columns: 1fr !important; /* 手机端完全单栏切换 */
  }

  .section-title {
    margin-bottom: 2.5rem;
  }
  
  .section-title h2 {
    font-size: 1.75rem;
  }

  .footer-nav {
    flex-direction: column; /* 手机端页脚单栏，适合手指操作 */
    gap: 1.25rem;
  }

  .content-card {
    padding: 1.75rem;
  }
}